The art with respect to plastic bags, and their production from continuous webs, is well-developed. By way of illustration, U.S. Pat. No. 3,420,433 discloses a bag having a U-folded closure flap. The closure flap of that patent has an adhesive stripe on the inner portion of the flap covered by the U-fold.
As an additional illustration of the art, U.S. Pat. No. 3,519,197 discloses a bottom gusseted bag having a Z-folded top portion which forms the mouth of the bag. The Z-fold of that patent contains a line of weakness that may be torn readily to permit access to the interior of the bag.
As yet another illustration of the prior art, U.S. Pat. No. 3,990,627 discloses, in FIG. 4 thereof, an adhesive closure bag with a Z-folded flap. However, no method of making the bag of that patent is disclosed therein.
As still another illustration of the prior art, U.S. Pat. No. 3,942,713 discloses a double-flapped bag wherein the rear flap forms a pouch and wherein the front flap has an adhesive strip on the inner portion of the flap covered by a Z-fold.
In view of the commercial importance of plastic bags, there exists a considerable need for new types of bags and methods for making them.